DNA oxidation in anionic reverse micelles: ruthenium-mediated damage at Guanine in single- and double-stranded DNA.
Publication/Presentation Date
4-3-2006
Abstract
One-electron guanine oxidation in DNA has been investigated in anionic reverse micelles (RMs). A photochemical method for generating Ru3+ from the ruthenium polypyridyl complex tris(2-2'-bipyridine)ruthenium(II) chloride ([Ru(bpy)3]Cl2) is combined with high-resolution polyacrylamide gel electrophoresis (PAGE) to quantify piperidine-labile guanine oxidation products. As characterized by emission spectroscopy of Ru(bpy)3(2+), the addition of DNA to RMs containing Ru(bpy)3(2+) does not perturb the environment of Ru(bpy)3(2+). The steady-state quenching efficiency of Ru(bpy)3(2+) with K3[Fe(CN)6] in buffer solution is approximately 2-fold higher than that observed in RMs. Consistent with the difference in quenching efficiency in the two media, a 1.5-fold higher yield of piperidine-labile damage products as monitored by PAGE is observed for duplex oligonucleotide in buffer vs RMs. In contrast, a 13-fold difference in the yield of PAGE-detected G oxidation products is observed when single-stranded DNA is the substrate. Circular dichroism spectra showed that single-stranded DNA undergoes a structural change in anionic RMs. This structural change is potentially due to cation-mediated adsorption of the DNA phosphates on the anionic headgroups of the RMs, leading to protection of the guanine from oxidatively generated damage.
Volume
45
Issue
7
First Page
3124
Last Page
3132
ISSN
0020-1669
Published In/Presented At
Evans, S. E., Mon, S., Singh, R., Ryzhkov, L. R., & Szalai, V. A. (2006). DNA oxidation in anionic reverse micelles: ruthenium-mediated damage at Guanine in single- and double-stranded DNA. Inorganic chemistry, 45(7), 3124–3132. https://doi.org/10.1021/ic0521022
Disciplines
Medicine and Health Sciences
PubMedID
16562969
Department(s)
Fellows and Residents
Document Type
Article